The AMS Alpha Nissan GT-R 90mm Cast Downpipes are the largest free-flowing downpipes available on the market. On already upgraded GT-Rs AMS saw this bolt-on add 100 whp and improve turbo spool by 400 RPM, so these are a huge upgrade over OE downpipes.

Designed by the AMS engineering team in Solidworks, the inlet and outlets were designed to optimize exhaust flow. Most systems implement 76mm downpipes that can cause unnecessary back-pressure, but AMS uses a larger 90mm primary pipe that optimizes exhaust flow, freeing up horsepower and improving spool time.
In addition the AMS downpipes feature stainless steel cast construction which provide OE reliability.

With unrivaled fitment, finish, and performance the AMS Nissan GT-R 90mm cast Downpipes are a great upgrade to support any future modifications!